Pipe-wrench



(No Model.)

J. E. MQDONALD.-

PIPE WRENCH.

No; 606,572. 4 Patented June-28,1898.

amnion willimwo UNITED STATES PATENT ()FFICE.

JAMES E. MQDONALD, OF EVANSVILLE, INDIANA.)

PIPE-WRENCH.

SPECIFICATION formingpart of Letters Patent No. 606,572, dated June 28, 1898. Application filed November 4, 1897. Serial No. 657,323. (No model.)

To all whom it may concern:

Be it known that I, JAMES E. MCDONALD, a citizen of the United States,residing at Evansville, in the county of Vanderburg and State of Indiana, have invented a new andusefu'l PipeWrench,of which the following is a specification.

My invention relates to wrenches, and more particularly to that class of wrenches used upon rods, pipes, or like cylindrical bodies and known to the trade and public as pipewrenches. I 1

The object of my invention is to simplify and cheapen-the construction of such wrenches, while rendering them more efiective and durable.

With this object in view my invention consists in the improved construction, arrangement, and combination of parts hereinafter fully described, and afterward specifically pointed out'in the appended claims.

In order to enable others skilled in the art to which my invention most nearly appertains to make and use the same, I will now proceed to describe its construction and operation, reference being had tothe accompanying drawings, forming part of this speci fication, in whicha Figure 1- is a perspective view illustrating a pipe-wrench made in accordance with my invention with a piece of pipe held in position for turning. I Fig. 2 is a vertical longitudinal sectional view taken on a plane cutting through the sliding stirrup alongside of the handle-bar, showing also the pipe held in position to be turned by thewrench. Fig. 3 is a similar view with the block in position to admit of the backward sliding of it and the from the point where the bar and head come together for some distance along the bar, as at E, the teeth pointing toward the head B. F indicates a-sliding stirrup loosely fitted ,over the bar A, its ends G G projecting beyond the edge'D of the bar.

' Hindicates a freely-rocking dog or block pivotally secured by means of a pin, rivet, or

screw I between the legs G' G of the stirrup F at a point far enough from the toothed edge of the bar'A to leave a space sufficient for clearance when moving the dog and stirrup upon the bar. The inner edge or face J of the dog H, opposite the teeth E of the bar, is plain or smooth, and at its outer end a tooth K is raised above the surface, pointing in the opposite direction in order to permit of its being engaged with said teeth when desired. Y It will be noticed that the pivot-pin I'passes through the dog H at a point in the rear of the middle'vertical line of the dog, leaving much the larger portion of the dog forward of the pivot. The forward face L of the dog, opposite to the teeth 0 of the head B when in operative position, inclines back from its inner end M to its outer end N. The end or corner Mis slightly beveled off, as shown.

In the embodiment of my invention illus-- trated I have shown the dog as of a quadrilateral form; but this is not at all essential, as it may be of any desired contour, provided only that its innerand forward faces be constructed as described, these faces'forming the only operative portions.

O is a section of pipe shown as held in position to be turned in Figs. 1 and 2.

The construction of my improved pipewrench will be readily understood from the foregoing description, and its operation may be described as follows:

When it is desired to turn a pipe or other round or cylindrical body, the stirrup F is moved backward on the bar A until the toothed inner face of head B and the forward face L of the dog II are far enough apart to admit the pipe between them, as shown in Figs. 1v and 2, when by pressing downward on handle A the dog Hwill squeeze the pipe 0 between its forward face L and the teeth 0 of head B, the tooth Kengaging one of the teeth E of the bar and the pipe engaging the teeth 0 of the head B. The

side of the pipe 0 opposite to that engaging the teeth 0 is in contact with the forward face L of the dog II, and a straight line drawn from the tooth K of the dog and the point of engagement of the pipe 0 with the teeth 0 will pass above the point of contact of pipe 0 with the face L of dog II. It will there fore be obvious that pressure downward on handle-bar A will cause the dog II and pipe 0 to act as toggle-levers, one lever being represented by a straight line running from the point of contact of the pipe 0 and teeth C and the point of contact of the other side of the pipe 0 with face L of the dog II and the other lever by a line drawn from tooth K of dog II. to the point of contact of pipe 0 with face L of dog II, while the pivot of the two levers is represented by the point of contact of the pipe 0 with the face L of dog II. \Vhen the handle is pressed downward, the pressure and strain of gripping the pipe will be exerted on the lines representing these levers, and as the point of contact of the pipe with the dog is moved inward by continued pressure on the handle the pivot-pin on which the dog is hung also moves inward, carrying the stirrup F with it and clearing the stirrup from contact with the outer edge of the bar A, as shown most clearly in Fig. 2, so that it is free to swing on the pivot-pin, as shown by dotted lines in Fig. 2, there being no strain whatever on the pin.

The adjustment of the dog and stirrup on the handle-bar ranges from a point very near to the head, in which adjustment the beveled corner M of the dog II rests against the smooth portion P of the inner face of the head B, to a point distant therefrom equal to the diameter of a pipe whose radius is not longer than a straight line drawn from the teeth E to a straight line drawn from the outer tooth C of the head to the lower end of the face L of the dog II.

The construction and operation of my improved pipe-wreneh will be readily understood from the foregoing description, and the simplicity, cheapness, durability, and eifectiveness of my invention will be apparent.

The parts are all extremely simple and cheap to construct, and there is a minimum of liability to wear or breakage in ordinary use. The adjustments are extremely easy to make, and the action is certain and quick.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is-

1. An improved pipe-wrench consisting of a rateheted bar having a fixed jaw, a stirrup loosely mounted on said bar, having its legs extending below the under edge of said bar, a block or dog pivotally mounted between said arms, free to rock and having a tooth or pawl at the upper angle of its top and rear side and normally out of engagement with the toothed or serrated under edge of the bar, and with the cross-bar of the stirrup resting on the upper edge of the bar said dog or block and the legs of the stirrup adapted to move backward upon the initial contact with the pipe whereby the tooth or pawl is forced into contact with the serrated surface of the bar and the cross-bar of the stirrup is raised above the upper edge of the bar.

2. In a wrench and in combination with a rateheted bar having a fixed jaw, a pivoted jaw having a tooth or pawl and a grippingface made smooth and declining downwardly, a stirrup straddling the bar and having spaced legs between which the pivoted jaw is mounted and free to rock, said stirrup normally resting directly on the upper edge of the rateheted bar to maintain the pivoted jaw normally out of contact with the ratchetsurface of said bar, the legs of the stirrup and the pivoted jaw moving rearward upon the initial contact with the object to be gripped whereby the tooth or pawl of the pivoted jaw is thrown into contact with the ratchet-surface of the bar and the stirrup is raised to elevate its cross-bar above the upper edge of the rateheted bar.

JAMES E. MCDONALD.

\Vitnesses:

CHAS. E. RIORDAN, CHAS. E. 311001;. 

